Why Choose an Investment Casting?

An investment casting is multi layered process that is designed to yield high production rates, particularly for small or highly complex components that require a superior surface finish. For quality to cost, the process offers unrivalled performance benefits.

The method also does away with the need for course machining as well as allowing for a greater diversity in design.

A wax mould of the component to be cast is produced by injection-moulding high-technology wax into a metal die. A number of wax components are then mounted on to a wax runner which is then dipped (or invested) in to a ceramic slurry. Further layers are added and then dried to give the shell sufficient durability for the molten metal.

The wax is removed (for this reason, the process is sometimes called a lost wax process) and the shell is then fired to leave a ceramic impression of the part to be cast, in to which molten metal is poured.

Once the metal has cooled, the shell is removed leaving a casting that requires little or no finishing.

Tools are generally quicker and lower cost to produce than with alternative casting methods, they last longer and are easily modified. Castings can be produced in a wide range of metals.

Interesting Fact

The investment casting process, also known as the lost wax method has been in use for thousands of years. The ancient Egyptians used this process to make jewellery and other ornate objects.

Casting Tolerances and Metals

Linear
Up to 13mm +/- 0.08mm	(up to 1/2" +/- 0.003)
Up to 25mm +/- 0.13mm	(up to 1” +/- 0.0005)
Over 25mm + 0.13mm per 25mm	(over 1” +/- 0.0005 per inch)
Angular Tolerances
No closer than +/- 0.5 degrees
Holes
Up to 6mm + 0.08mm	(up to 1/2" + 0.003)
Up to 25mm + 0.13mm	(up to 1" + 0.005)
Over 25mm + 0.10 per 25mm	(over 1" + 0.004 per inch)
Concentricity
Outside diameter	18mm          25mm          38mm          51mm
Inside diameter	6mm          13mm          19mm          25mm
T.I.R Eccentricity	0.2mm       0.25mm        0.3mm       0.38mm
Ovality
Diameter	up to 13mm      13mm to 25mm       25mm to 38mm
Ovality T.I.R	0.25mm        0.3mm           0.4mm
Flatness
	+ 0.1mm per 25mm depending on configuration
Draft Angles
	Not required
Ingate witness
	A witness of approximately 0.25mm will be left in position shown on the marked up drawing sent with our Form of Supply.

Materials

Parts can be cast in a wide range of materials.

• Stainless Steel
• Carbon Steel
• Aluminium
• Brass
• Bronze
• Tool Steel
• Cast Iron
• Nickel Alloys
• Cobalt Alloys
• Other metals can also be cast, please contact us for more details.